Light emitting device

ABSTRACT

A light emitting device includes at least one layer below or above a reflective layer to prevent delamination of the reflective layer from a layer below and/or above the reflective layer.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority under 35 U.S.C. §119(a) ofKorean Patent Application No. 10-2013-0064394 (filed on Jun. 5, 2013),which is hereby incorporated by reference in its entirety.

BACKGROUND

1. Field

The embodiment relates to a light emitting device.

2. Background

The embodiment relates to a light emitting device.

The embodiment relates to a light emitting device package.

Studies for a light emitting device package having a light emittingdevice have been actively pursued.

A light emitting device, which is made of, for example, a semiconductormaterial, is a semiconductor light emitting device or a semiconductorlight emitting diode to convert electrical energy into light energy.

When comparing with conventional light sources such as a fluorescentlamp, and an incandescent lamp, the semiconductor light emitting devicehas advantages such as low power consumption, a semi-permanent lifespan, a rapid response speed, safety, and an eco-friendly property. Inthis regard, various studies have been performed to replace theconventional light sources with the LEDs.

The light emitting devices or light emitting device packages areincreasingly used as light sources for lighting devices, such as variouslamps used in indoors and outdoors, liquid crystal displays, electricsignboards, and street lamps.

The above references are incorporated by reference herein whereappropriate for appropriate teachings of additional or alternativedetails, features and/or technical background.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments will be described in detail with reference to thefollowing drawings in which like reference numerals refer to likeelements wherein:

FIG. 1 is a plan view showing a light emitting device according to afirst embodiment.

FIG. 2 is a sectional view showing the light emitting device taken alongline H-H′ of FIG. 1.

FIG. 3 is a sectional view showing the light emitting device taken alongline I-I′ of FIG. 1.

FIG. 4 is a view illustrating the relationship between a width of thedelamination prevention layer and a width of a circumference thereofshown in FIG. 1.

FIG. 5 is a sectional view showing a light emitting device according toa second embodiment.

FIG. 6 is a plan view showing the delamination prevention layer of FIG.5.

FIG. 7 is a sectional view showing a light emitting device according toa third embodiment.

FIG. 8 is a sectional view showing a light emitting device packageaccording to an embodiment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

In the description of embodiments, it will be understood that when anelement is referred to as being ‘on (under) or under (on)’ anotherelement, it can be directly on another element or at least oneintervening element may also be present. Further, when it is expressedas ‘upward (downward) or downward (upward)’, it may include the upwarddirection as well as the downward direction on the basis of one element.

FIG. 1 is a plan view showing a light emitting device according to afirst embodiment, FIG. 2 is a sectional view showing the light emittingdevice taken along line H-H′ of FIG. 1, and FIG. 3 is a sectional viewshowing the light emitting device taken along line I-I′ of FIG. 1.

Referring to FIGS. 1 to 3, the light emitting device 1 according to thefirst embodiment may include a growth substrate 2, a light emittingstructure 12, a reflective electrode 14, and first and second bumps.

The light emitting device 1 according to the first embodiment may be aflip-chip type light emitting device, but the first embodiment is notlimited thereto.

The light emitting device 1 according to the first embodiment mayfurther include a plurality of first electrode pads 18 and a pluralityof second electrode pads 20, but the first embodiment is not limitedthereto.

The light emitting device 1 according to the first embodiment mayfurther include first and second bump pads 28 and 30, but the firstembodiment is not limited thereto.

The light emitting device 1 according to the first embodiment mayfurther include a buffer layer 4, but the first embodiment is notlimited thereto.

The light emitting device 1 according to the first embodiment mayfurther include at least one compound semiconductor layer which isdisposed on and/or under the light emitting structure 12, but the firstembodiment is not limited thereto.

The buffer layer 4 and the light emitting device 12 may be formed of agroup II-VI compound semiconductor material or a group III-V compoundsemiconductor material. For example, the buffer layer 4 and the lightemitting structure 12 may include at least one selected from the groupconsisting of InAlGaN, GaN, AlGaN, InGaN, AlN, InN, and AlInN, but theembodiment is not limited thereto.

The growth substrate 2 is used to grow the light emitting structure 12while supporting the light emitting structure 12. The growth substrate 2may include a material suitable to grow a semiconductor material. Thegrowth substrate 2 may include a material having thermal stability and alattice constant approximate to that of the light emitting structure 12.The growth substrate 2 may be one of a conductive substrate, a compoundsemiconductor substrate and an insulating substrate, but the embodimentis not limited thereto.

The growth substrate 2 may include at least one selected from the groupconsisting of Sapphire (Al2O3), SiC, Si, GaAs, GaN, ZnO, GaP, InP andGe.

The growth substrate 2 may include dopants such that the growthsubstrate 2 has conductivity, but the embodiment is not limited thereto.The growth substrate 2 including the dopants may serve as an electrodelayer, but the embodiment is not limited thereto.

The buffer layer 4 may be interposed between the growth substrate 2 andthe light emitting structure 12, but the embodiment is not limitedthereto.

The buffer layer 4 may reduce the difference between the latticeconstants of the growth substrate 2 and the light emitting structure 12.In addition, the buffer layer 4 may prevent the material of the growthsubstrate 2 from being diffused into the light emitting structure 12,prevent a melt-back phenomenon such as a recess formed in the topsurface of the growth substrate 2, or prevent the growth substrate 2from being broken by controlling strain, but the embodiment is notlimited thereto.

The buffer layer 4 may be formed on the growth substrate 2 and the lightemitting structure 12 may be formed on the buffer layer 4. That is, thebuffer layer 4 may be formed between the growth substrate 2 and thelight emitting structure 12.

The light emitting structure 12 may be formed on the buffer layer 4.Since the light emitting structure 12 is grown on the buffer layer 4having a lattice constant similar to a lattice constant of the lightemitting structure 12, the defect, such as a dislocation, may bereduced.

The light emitting structure 12 may include a plurality of compoundsemiconductor layers.

For example, the light emitting structure 12 may include at least afirst conductive semiconductor layer 6, an active layer 8, and a secondconductive semiconductor layer 10, but the embodiment is not limitedthereto.

The active layer 8 may be disposed on the first conductive semiconductorlayer 6, and the second conductive semiconductor layer 10 may bedisposed on the active layer 8.

The first conductive semiconductor layer 6, the active layer 8, and thesecond conductive semiconductor layer 10 may be realized by using agroup II-VI or III-V compound semiconductor material having acomposition formula of AlxInyGa(1-x-y)N (0≦x≦1, 0≦y≦1, and 0≦x+y≦1). Forexample, The first conductive semiconductor layer 6, the active layer 8,and the second conductive semiconductor layer 10 may include at leastone selected from the group consisting of InAlGaN, GaN, AlGaN, InGaN,AlN, InN and AlInN, but the embodiment is not limited thereto.

For example, the first conductive semiconductor layer 6 may be an N-typesemiconductor layer including N-type dopant, and the second conductivesemiconductor layer 10 may be a P-type semiconductor layer includingP-type dopants, but the embodiment is not limited thereto. The N-typedopants include Si, Ge, and Sn, and the P-type dopants include Mg, Zn,Ca, Sr, and Ba, but the embodiment is not limited thereto.

The active layer 8 emits light having a wavelength corresponding to anenergy band gap between the materials constituting the active layer 8 bycombining the first carrier, for example, electrons injected through thefirst conductive semiconductor layer 6 with the second carrier, forexample, holes injected through the second conductive semiconductorlayer 10.

The active layer 8 may include one of an MQW (multiple quantum well)structure, a quantum wire structure or a quantum dot structure. Theactive layer 8 may have well layers and barrier layers repeatedly formedat one cycle of a well layer and a barrier layer. The repetition cycleof a well layer and a barrier layer may be varied depending on thecharacteristics of the light emitting device, but the embodiment is notlimited thereto.

For example, the active layer 8 may be formed in the stack structure ofInGaN/GaN, InGaN/AlGaN, InGaN/InGaN. The energy bandgap of the barrierlayer may be greater than energy the bandgap of the well layer.

Although not shown, a third conductive semiconductor layer may bedisposed under the first conductive semiconductor layer 6 and/or on thesecond conductive semiconductor layer 10. For example, the thirdconductive semiconductor layer disposed under the first conductivesemiconductor layer 6 may include the same conductive dopant as that ofthe second conductive semiconductor layer 10, but the embodiment is notlimited thereto. For example, the third conductive semiconductor layerdisposed on the second conductive semiconductor layer 10 may include thesame conductive dopant as that of the first conductive semiconductorlayer 6, but the embodiment is not limited thereto.

The reflective electrode 14 may be formed on the light emittingstructure 12. In detail, the reflective electrode 14 may be formed onthe second conductive semiconductor layer 10.

The reflective electrode 14 may have a ‘T’ shape viewed from the top,but the embodiment is not limited thereto.

The reflective electrode 14 may include a material having a reflectiveproperty and superior electric conductivity. For example, the reflectiveelectrode 14 may include one selected from the group consisting of Ag,Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, and Hf or the multilayeredstructure thereof.

The reflective layer 14 may include Ag/Ni/Ti/TiW/Ti or a laminationthereof, but the embodiment is not limited thereto. The Ag has areflective function, The Ni has a junction function or a diffusionprevention function, the Ti has a junction function, and the TiW has thediffusion prevention function, but the embodiment is not limitedthereto.

The reflective electrode 14 may make contact with a top surface of thesecond, but the embodiment is not limited thereto.

When the reflective electrode 14 does not make ohmic contact with thesecond conductive semiconductor layer 10, a transparent electrode layerrepresenting a superior ohmic contact characteristic with the secondconductive semiconductor layer 10 may be interposed between thereflective electrode 14 and the second conductive semiconductor layer10, but the embodiment is not limited thereto.

The transparent electrode layer may include a conductive material havingsuperior light transmittance. For example, the transparent electrode mayinclude at least one selected from the group consisting of ITO, IZO(In—ZnO), GZO (Ga—ZnO), AZO (Al—ZnO), AGZO (Al—Ga ZnO), IGZO (In—GaZnO), IrOx, RuOx, RuOx/ITO, Ni/IrOx/Au and Ni/IrOx/Au/ITO or themultilayered structure thereof, but the embodiment is not limitedthereto.

A first electrode pad 18 may be formed on the first conductivesemiconductor layer 6, and a second electrode pad 20 may be formed onthe reflective electrode 14, but the embodiment is not limited thereto.

Each of the first and second electrode pads 18 and 20 may include acircular pattern, but the embodiment is not limited thereto.

The first and second electrode pads 18 and 20 may include a materialhaving superior electric conductivity. The first and second electrodepads 18 and 20 may include one selected from the group consisting of Al,Ti, Cr, Ni, Pt, Au, W, Cu, and Mo, or the multilayered structurethereof, but the embodiment is not limited thereto.

For example, the first and second electrode pads 18 and 20 may includeCr/Ni/Ti/TiW/Ti or a lamination thereof, but the embodiment is notlimited thereto. The Cr has an electrode function, The Ni has a junctionfunction or a diffusion prevention function, the Ti has a junctionfunction, and the TiW has the diffusion prevention function, but theembodiment is not limited thereto.

A first bump pad 22 may be formed on the first electrode pad 18, and asecond bump pad 24 may be formed on the second electrode pad 20, but theembodiment is not limited thereto.

The first and second bump pads 22 and 24 may allow the first bump 28 andthe second bump 30 to be easily bonded, and may stably support the firstand second bumps 28 and 30, but the embodiment is not limited thereto.

When viewed from the top, the first bump pad 22 may have a ‘□’shape, andthe second bump pad 24 may have a ‘T’ shape, but the embodiment is notlimited thereto. The second bump pad 24 may vertically overlap with theentire region of the reflective electrode 14, but the embodiment is notlimited thereto. When viewed from the top, the first bump pad 22 maysurround one side region of the second bump pad 24, but the embodimentis not limited thereto.

Similar to the first and second electrode pads 18 and 20, the first andsecond bump pads 22 and 24 may include a material having superiorelectric conductivity. The first and second bump pads 22 and 24 mayinclude one selected from the group consisting of Al, Ti, Cr, Ni, Pt,Au, W, Cu, and Mo, or the multilayered structure thereof, but theembodiment is not limited thereto.

The first bump pad 22 may vertically overlap with the first electrodepads 18. The second bump pad 24 may vertically overlap with the secondelectrode pads 20.

The first and second electrode pads 18 and 20 and/or the first andsecond bump pads 22 and 24 are not essential elements. When the firstand second electrode pads 18 and 20 and/or the first and second bumppads 22 and 24 are omitted, the first and second bumps 28 and 30 may bedirectly formed on the first conductive semiconductor layer 6 and thereflective electrode 14, respectively. That is, the first bump 28 maymake contact with a top surface of the first conductive semiconductorlayer 6, and the second bump 30 may make contact with a top surface ofthe reflective electrode 14, but the embodiment is not

The first and second bumps 28 and 30 are used to electrically connectthe light emitting device 1 according to the first embodiment to firstand second electrode layers disposed at a light emitting device packagewhile supporting the light emitting device 1 according to the firstembodiment, but the embodiment is not limited thereto.

Similar to the first and second electrode pads 18 and 20 and/or thefirst and second bump pads 22 and 24, the first and second bumps 28 and30 may include a material having superior electric conductivity. Thefirst and second bump pads 22 and 24 may include one selected from thegroup consisting of Al, Ti, Cr, Ni, Pt, Au, W, Cu, and Mo, or themultilayered structure thereof, but the embodiment is not limitedthereto.

Each of the first and second bumps 28 and 30 may have a cylindricalstructure, but the embodiment is not limited thereto. That is, the firstand second bumps 28 and 30 may have a spherical sectional structure, butthe embodiment is not limited thereto.

The light emitting device 1 may further include a protective layer 26.The protective layer 26 may be formed along the circumference of thelight emitting structure 12, but the embodiment is not limited thereto.

The protective layer 26 may be formed on a partial region of the firstelectrode pad 18 and a partial region of the second electrode pad 20 aswell as the circumference of the light emitting structure 12.

The protective layer 26 may include an opening 27 on the secondelectrode pad 20, but the embodiment is not limited thereto. That is,the protective layer 26 may be formed on the entire area of the secondelectrode pad 20 except for the opening 27.

The protective layer 26 may include a material of a superior insulationcharacteristic. The protective layer 26 may include one selected fromthe group consisting of SiO2, SiOx, SiOxNy, Si3N4, and Al2O3, or themultilayered structure thereof, but the embodiment is not limitedthereto.

The protective layer 26 may prevent a short circuit from being formedbetween the first electrode pad 18 disposed on the first conductivesemiconductor layer 6 and the reflective electrode 14 and/or the secondelectrode pad 20 disposed on the first conductive semiconductor layer 6,and may prevent a short circuit from being formed between the firstelectrode pad 18 or the reflective electrode 14 and/or the secondelectrode pad 20 and the active layer 8.

Meanwhile, when the growth substrate 2 is directed upward in theflip-chip type light emitting device, the reflective electrode 14reflects light, which is generated from the active layer and travelleddownward, in the upward direction. Accordingly, the light extractionefficiency is increased so that the optical characteristic can beimproved.

However, the reflective electrode 14 represents inferior bondingcharacteristic with respect to other adjacent layers, for example, thesecond conductive semiconductor layer 10 and/or the second electrode pad20. That is, when external shock or stress is applied to the reflectiveelectrode 14, the reflective electrode 14 may be delaminated from theadjacent layer.

When the light emitting device 1 according to the first embodiment ismounted on a body of a light emitting device package, the first andsecond bumps 28 and 30 of the light emitting device 1 are melted by heathaving a high temperature and then cooled, so that the light emittingdevice 1 may be attached to first and second electrode layers disposedon the body. When the first and second bumps 28 and 30 are cooled afterbeing melted, stress such as compressive force is caused at the firstand second bumps 28 and 30. The stress exerts influence upon thereflective electrode 14 through the second bump pad 24 and the secondelectrode pad 20. Accordingly, the reflective electrode 14 isdelaminated from the second conductive semiconductor layer 10 or thesecond electrode pad 20 due to the stress caused by the second bump 30.

According to the first embodiment, a delamination prevention layer 16may be formed between the reflective electrode 14 and the secondelectrode pad 20. That is, the delamination prevention layer 16 may makecontact with a top surface of the reflective electrode 14 and may makecontact with a bottom surface of the second electrode pad 20.

When the second electrode pad 20 is not formed, the delaminationprevention layer 16 may make contact with a bottom surface of the secondbump pad 24, but the embodiment is not limited thereto.

When the second electrode pad 20 and the second bump pad 24 are notformed, the delamination prevention layer 16 may make contact with thebottom surface of the second bump 30, but the embodiment is not limitedthereto.

The delamination prevention layer 16 may absorb the stress caused by thesecond bump 30 so that the stress may not be further applied to thereflective electrode 14 anymore.

Further, the delamination prevention layer 16 may represent superioradhesion force with the reflective electrode 14 so the delaminationprevention layer 16 may prevent the reflective electrode 14 from beingdelaminated.

Although the first embodiment has been described that the delaminationprevention layer 16 is formed on the reflective electrode 14, anotherdelamination prevention layer 16 may be formed under the reflectiveelectrode 14. That is, another delamination prevention layer 16 may beformed between the second conductive semiconductor layer 10 and thereflective electrode 14, but the embodiment is not limited thereto. Inthis case, even when the stress from the second bump 30 is applied tothe reflective electrode 14, the reflective electrode 14 may be preventfrom being delaminated by another delamination prevention layer 16.

The delamination prevention layer 16 may include an inorganic insulationmaterial, but the embodiment is not limited thereto. Like the protectivelayer 26, the delamination prevention layer 16 may include a material ofa superior insulation characteristic. The delamination prevention layer16 may include one selected from the group consisting of SiO2, SiOx,SiOxNy, Si3N4, and Al2O3, or the multilayered structure thereof, but theembodiment is not limited thereto.

Although the delamination prevention layer 16 is formed, since thereflective electrode 14 is electrically connected to the secondelectrode pad 20, the second electrode pad 20 may make contact with atop surface of the reflective electrode 14 while interposing thedelamination prevention layer 16, but the embodiment is not limitedthereto.

For example, the second electrode pad 20 may surround the delaminationprevention layer 16. That is, the second electrode pad 20 may include afirst region formed on the delamination prevention layer 16 and a secondregion extending downward from an edge of the first region on a side ofthe delamination prevention layer 16. The second region of the secondelectrode pad 20 may make contact with a top surface of the reflectiveelectrode 14.

As shown in FIG. 4, a width of the delamination prevention layer 16 isX, a width of the second electrode pad 20 is Y, and a diameter of anopening 27 of the protective layer 26 is Z. In this case, therelationship among the width X of the delamination prevention layer 16,the width Y of the second electrode pad 20, and the diameter Z of anopening 27 of the protective layer 26 may be expressed by a followingequation 1.Z<X<Y   [Equation 1]

-   -   X: 1    -   Y: 2 or greater    -   Z: 0.5˜1.0

The diameter Z of an opening 27 of the protective layer 26 may be atleast 50% based on the width X of the delamination prevention layer 16.When the diameter Z of an opening 27 of the protective layer 26 lessthan the 50% of the width X of the delamination prevention layer 16,since the diameter Z of an opening 27 of the protective layer 26 is verysmall, a contact area between the second electrode pad 20 and the secondbump pad 24 is reduced so that power may not be easily supplied.

The width Y of the second electrode pad 20 is at least twice greaterthan the width X of the delamination prevention layer 16. When the widthY of the second electrode pad 20 is not twice greater than the width Xof the delamination prevention layer 16, a width of the second region ofthe second electrode pad 20 is reduced. If the width of the secondregion of the second electrode pad 20 is reduced, a contact area betweenthe second electrode pad 20 and the reflective electrode 14 is reducedso that power may not be easily supplied.

FIG. 5 is a sectional view showing a light emitting device according toa second embodiment.

The second embodiment is substantially similar to the first embodimentexcept that the delamination prevention layer 16 is formed therein witha plurality of holes 32. In the following description of the secondembodiment, the constituent elements having the same function andstructure as those of the first embodiment will be assigned with thesame reference numerals and a detailed description thereof will beomitted.

Referring to FIG. 5, the light emitting device 1A according to thesecond embodiment may include a growth substrate 2, a light emittingstructure 12, a reflective electrode 14, and first and second bumps 28and 30.

The light emitting device 1A according to the second embodiment mayfurther include at least one of a plurality of first electrode pads 18and a plurality of second electrode pads 20, and first and second bumppads 22 and 24, but the second embodiment is not limited thereto.

The light emitting device 1A according to the second embodiment mayfurther include at least one compound semiconductor layer which isdisposed on and/or under the light emitting structure 12, but the secondembodiment is not limited thereto.

According to the second embodiment, a delamination prevention layer 16may be formed between the reflective electrode 14 and the secondelectrode pad 20. That is, the delamination prevention layer 16 may makecontact with a top surface of the reflective electrode 14 and may makecontact with a bottom surface of the second electrode pad 20.

As shown in FIG. 6, the delamination prevention layer 16 may include aplurality of holes 32. The holes 32 may be randomly or constantlyformed.

The second electrode pad 20 may make contact with the reflectiveelectrode 14 through the holes 32 of the delamination prevention layer16.

Further, the second electrode pad 20 may surround an outer side of thedelamination prevention layer 16 to make contact with a top surface ofthe reflective electrode 14, but the embodiment is not limited thereto.

The second electrode pad 20 may make contact with the reflectiveelectrode 14 through the circumference of the delamination preventionlayer 16.

Although not shown, when a plurality of holes 32 are formed at thedelamination prevention layer 16 so that a contact area between thesecond electrode pad 20 and the reflective electrode 14 is ensuredthrough the holes 32 to easily supply power, a diameter of thedelamination prevention layer 16 may be the same as a width of thereflective electrode 14 and/or a width of the second electrode 20. Inthis case, a side of the delamination prevention layer 16 may makecontact with an inner side of the protective layer 26, but theembodiment is not limited thereto.

FIG. 7 is a sectional view showing a light emitting device according toa third embodiment.

The third embodiment is substantially similar to the first embodimentexcept that the delamination prevention layer 16 is formed at otherregions except for under the second bump 30.

In the following description of the third embodiment, the constituentelements having the same function and structure as those of the firstembodiment will be assigned with the same reference numerals and adetailed description thereof will be omitted.

Referring to FIG. 7, the light emitting device 1B according to the thirdembodiment may include a growth substrate 2, a light emitting structure12, a reflective electrode 14, and first and second bumps 28 and 30.

The light emitting device 1B according to the third embodiment mayfurther include at least one of a plurality of first electrode pads 18and a plurality of second electrode pads 20, and first and second bumps28 and 30, but the second embodiment is not limited thereto.

The light emitting device 1A according to the third embodiment mayfurther include at least one compound semiconductor layer which isdisposed on and/or under the light emitting structure 12, but the thirdembodiment is not limited thereto.

According to the third embodiment, a delamination prevention layer 16may be formed between the reflective electrode 14 and the secondelectrode pad 20. That is, the delamination prevention layer 16 may makecontact with a top surface of the reflective electrode 14 and may makecontact with a bottom surface of the second electrode pad 20.

Further, the delamination prevention layer 16 may be formed not onlyunder the second bump 30, but also on various regions other than thesecond bump 30.

The delamination prevention layer 16 may be formed along the reflectiveelectrode 14 having a ‘T’ shape, but the embodiment is not limitedthereto. The second electrodes 20 may be formed on the delaminationprevention layer 16.

The second bump pad 24 may cover the delamination prevention layer 16.The bump pad 24 may be formed on a top surface and a side of thedelamination prevention layer 16, and may make contact with a topsurface of the reflective electrode 14.

Although not described in the first to third embodiments, the secondbump 30 may be formed at regions in which the second electrode pad 20 isnot formed. That is, the second bump 30 may be formed on the reflectiveelectrode 40 between the second electrode pads 20. In a case of thisstructure, the delamination prevention layer 16 according to the firstto third embodiments may not be formed under the second bump 30.

Although not shown, the first electrode pads 18 and/or second electrodepads may be electrically insulated from each other through theprotective layer 26, and top surface of the first and second electrodepads 18 and 20 may be electrically connected to the first and secondbump pads 22 and 24, but the embodiment is not limited thereto.

FIG. 8 is a sectional view showing a light emitting device packageaccording to an embodiment.

Referring to FIG. 8, the light emitting device package may include alight emitting device 1 to generate light and a body 105 on which thelight emitting device 1 is mounted.

The light emitting device 1 may include flip-chip type light emittingdevices according to the first to third embodiments, but the embodimentis not limited thereto.

The body 105 may be formed in an upper region thereof with a cavity 111having an inclined surface and recessed downward, but the embodiment isnot limited thereto. In other words, the cavity 111 may include theinclined surface and a flat bottom surface, but the embodiment is notlimited thereto. An inner side of the cavity 111 may have a verticalsurface vertical to the bottom surface, but the embodiment is notlimited thereto.

The first and second electrode layers 107 and 109 may be formed throughthe body 105. The first electrode layer 107 may be electricallyinsulated and spaced apart from the second electrode layer.

The first and second electrode layers 107 and 109 may be formed on alateral side of the body 105 while being horizontally formed through thebody 105. Although not shown, the first and second electrode layers 107and 109 may be formed on a bottom surface of the body 105 while beingvertically formed through the body 105.

The first and second electrode layers 107 and 109 may be formed on abottom surface of the cavity 111.

The first and second electrode layers 107 and 109 may include a metallicmaterial, such as copper (Cu), aluminum (Al), chrome (Cr), platinum(Pt), nickel (Ni), titanium (Ti), gold (Au), or W (tungsten),representing superior electric conductivity and superior corrosionresistance, but the embodiment is not limited thereto.

A material constituting the body 105 is injected through an injectionmolding process in the state that the first and second electrodes layers107 and 109 are provided, and hardened to form the body 105, so that thefirst and second electrode layers 107 and 109 may fix the body 105, butthe embodiment is not limited thereto.

The first and second electrode layers 107 and 109 may include a singlelayer or a multi-layer, but the embodiment is not limited thereto. Theuppermost layer in the first and second electrode layers 107 and 109 mayinclude a protective layer such Ag, but the embodiment is not limitedthereto.

The first and second bumps 28 and 30 of the light emitting device 1 maybe physically fixed to and electrically connected with the first andsecond electrodes 107 and 109 through a solder paste 101, respectively.

To this end, the first and second bumps 28 and 30 are melted by heathaving a high temperature and then cooled. The stress is caused bycompressive force due to cooling of the first and second bumps 28 and30, and the stress may delaminate the reflective electrode 14 of thelight emitting device.

In order to prevent such a delamination, a delamination prevention layer16 may be formed between the reflective electrode 14 and the secondelectrode pad 20. Since the stress generated from the second bump 30 isabsorbed by the delamination prevention layer 16, the reflectiveelectrode 14 may be prevented from being delaminated.

The molding member 113 may surround the light emitting device 1. Themolding member 113 may be formed in the cavity 111. That is, the moldingmember 113 may be filled in the cavity 111.

The molding member 113 may contain a phosphor to convert the wavelengthof light, but the embodiment is not limited thereto.

The top surface of the molding member 30 may be aligned line with thetop surface of the body 105, or may be higher than or lower than the topsurface of the body 105, but the embodiment is not limited thereto.

The molding member 113 may include a material representing atransmission characteristic, a heat radiation characteristic, and/or aninsulating characteristic. For example, the molding member 113 mayinclude a silicon material or an epoxy material, but the embodiment isnot limited thereto.

Although not shown, the light emitting device according to the first tothird embodiments is applicable to a COB (chip on board) light emittingdevice package, but the embodiment is not limited thereto. A pluralityof light emitting devices may be mounted on a sub-mount in the COB lightemitting device package, but the embodiment is not limited thereto.

The light emitting device and the light emitting device packageaccording to the embodiment are applicable to a light unit. The lightunit is applicable to a display device and a lighting device, forexample, a lighting lamp, a signal lamp, a headlight of a vehicle, anelectric signboard, and an indication lamp.

The embodiment provides a light emitting device capable of improvingreliability of a device.

The embodiment provides a light emitting device capable of preventing anelectrode from being delaminated.

The embodiment provides a light emitting device capable of improvinglight efficiency.

According to the embodiment, there is provided a light emitting deviceincluding: a substrate; a light emitting structure on the substrate andincluding a first conductive semiconductor layer, an active layer, and asecond conductive semiconductor layer; a reflective electrode on thesecond conductive semiconductor layer; a first bump on the reflectiveelectrode; and a first delamination prevention layer between thereflective electrode and the first bump.

According to the embodiment, there is provided a light emitting devicepackage including: a body having a cavity; first and second electrodelayers in the cavity; a light emitting device on the first and secondelectrode layers; and a molding member to surround the light emittingdevice.

According to the embodiment, since the delamination prevention layer isformed between the reflective electrode and an electrode pad so that thereflective electrode is prevented from being delaminated by thedelamination prevention layer, the reliability can be improved.

According to the embodiment, since the electrode pad is electricallyconnected to an outer side of the delamination prevention layer or iselectrically connected to the reflective electrode by passing throughthe delamination prevention layer, even if the delamination preventionlayer is formed, power may be easily supplied.

According to the embodiment, since the bump is electrically connected toa plurality of electrode pads, current may be rapidly supplied to theentire region of the light emitting device, so that the light efficiencycan be improved.

Any reference in this specification to “one embodiment,” “anembodiment,” “example embodiment,” etc., means that a particularfeature, structure, or characteristic described in connection with theembodiment is included in at least one embodiment of the invention. Theappearances of such phrases in various places in the specification arenot necessarily all referring to the same embodiment. Further, when aparticular feature, structure, or characteristic is described inconnection with any embodiment, it is submitted that it is within thepurview of one skilled in the art to effect such feature, structure, orcharacteristic in connection with other ones of the embodiments.

Although embodiments have been described with reference to a number ofillustrative embodiments thereof, it should be understood that numerousother modifications and embodiments can be devised by those skilled inthe art that will fall within the spirit and scope of the principles ofthis disclosure. More particularly, various variations and modificationsare possible in the component parts and/or arrangements of the subjectcombination arrangement within the scope of the disclosure, the drawingsand the appended claims. In addition to variations and modifications inthe component parts and/or arrangements, alternative uses will also beapparent to those skilled in the art.

What is claimed is:
 1. A light emitting device comprising: a substrate; a light emitting structure on the substrate and including a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer; a reflective electrode on the second conductive semiconductor layer; a second bump over the reflective electrode; and a first prevention layer provided between the reflective electrode and the second bump to prevent a delamination of the reflective electrode; and a second electrode pad and a second bump pad between the first prevention layer and the second bump, wherein the second electrode pad covers the first prevention layer.
 2. The light emitting device of claim 1, further comprising: a first bump on the first conductive semiconductor layer; and at least one of a first electrode pad and a first bump pad between the first conductive semiconductor layer and the first bump.
 3. The light emitting device of claim 2, wherein the first bump pad surrounds a lateral region of the second bump pad.
 4. The light emitting device of claim 1, further comprising a protective layer provided on an edge region between the second electrode pad and the second bump pad.
 5. The light emitting device of claim 4, wherein the protective layer is provided along a circumference of the light emitting structure, and wherein the protective layer includes an opening on the second electrode pad.
 6. The light emitting device of claim 5, wherein a diameter of the opening of the protective layer is at least 50% of a width of the first prevention layer.
 7. The light emitting device of claim 1, further comprising a second prevention layer under the reflective electrode to prevent a delamination of the reflective electrode.
 8. The light emitting device of claim 7, wherein a width of the second electrode pad is at least twice greater than a width of the second prevention layer.
 9. The light emitting device of claim 1, wherein the second electrode pad makes contact with the reflective electrode through a lateral side of the first prevention layer.
 10. The light emitting device of claim 1, wherein the first prevention layer makes contact with a top surface of the reflective electrode, and wherein the first prevention layer includes an insulation material.
 11. A light emitting device comprising: a substrate; a light emitting structure on the substrate and including a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer; a reflective electrode on the second conductive semiconductor layer; a second bump over the reflective electrode; and a prevention layer provided between the reflective electrode and the second bump, wherein the prevention layer includes a plurality of holes, and wherein the prevention layer prevents a delamination of the reflective electrode.
 12. The light emitting device of claim 11, further comprising at least one of a second electrode pad and a second bump pad between the first prevention layer and the second bump, wherein the second electrode pad makes contact with the reflective electrode through the holes.
 13. The light emitting device of claim 12, wherein the second electrode pad makes contact with the reflective electrode through a circumference of the prevention layer.
 14. The light emitting device of claim 12, wherein the reflective electrode includes one selected from the group consisting of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, and Hf.
 15. A light emitting device comprising: a substrate; a light emitting structure on the substrate and including a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer; a reflective electrode on the second conductive semiconductor layer; a second bump over the reflective electrode; a prevention layer between the reflective electrode and the second bump to prevent a delamination of the reflective electrode; a plurality of electrode pads on the prevention layer; and a second electrode pad between the prevention layer and the second bump, wherein a second bump pad is formed on a top surface and a lateral side of the prevention layer, and wherein the second electrode pad contacts with an upper portion of the prevention layer.
 16. The light emitting device of claim 15, wherein the second bump pad is between the prevention layer and the second bump, and wherein the prevention layer is formed to correspond to the second bump pad on the reflective electrode.
 17. The light emitting device of claim 16, wherein the reflective electrode includes a stack structure of Ag/Ni/Ti/TiW/Ti.
 18. The light emitting device of claim 16, further comprising a protective layer provided on an edge region between the second electrode pad and the second bump pad.
 19. The light emitting device of claim 18, wherein the protective layer is provided along a circumference of the light emitting structure, and wherein the protective layer includes an opening on the second electrode pad. 